The better the specs of a commercial product, the easier it would be to produce an open source version it, with coding and testing automation perhaps even a one-to-one offering.
More reliable than any specification, considering Windows itself is a patchwork of workarounds to not break backward-compatibility.
The better the specs of a commercial product, the easier it would be to produce an open source version it, with coding and testing automation perhaps even a one-to-one offering.